The present invention relates generally to materials testing, and more particularly to a method for manufacturing a test bar, to a test bar, and to apparatus associated therewith.
It is known to machine a test bar from a component, wherein the test bar is machined to include a gage section disposed between two longitudinal end portions. The gage section has a substantially rectangular cross section. Each longitudinal end portion terminates in a circular end face having a diameter larger than the width of the gage section. In one example, the longitudinal end portions of the test bar are secured to a materials testing device which places the test bar in tension to determine the strength of the gage section. In one application, test results are used to choose materials for the component, to choose dimensions for the component, etc.
Some components, such as some gas-turbine-engine casings, are too thin to have test bars machined therefrom because there is not enough material in the casing to machine the relatively large, circular, longitudinal end portions of a test bar needed to fit conventional testing devices. It is known to obtain a casing section from the casing wherein the casing section has a substantially rectangular cross section and serves as the gage section of a test bar. It is further known to weld, including inertia weld, end extensions to the casing section to create a test bar, wherein the end extensions have large, circular longitudinal end portions which fit conventional testing devices. However, because of the weldability of many alloys, this method has limited success in obtaining accurate test data.
Still, scientists and engineers continue to seek improved methods for manufacturing test bars.